html,body {
    margin: 0;
    padding: 0;
}
body {
    background-color: #454545;
}
.reg {
    width: 600px;
    height: 500px;
    margin: 100px auto;
    border: 10px solid #f5f5f7;
    background-color: white;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
}
.reg>span {
    font-weight: 600;
    font-size: 24px;
    color: black;
}
.reg form {
    border: 1px solid black;
    width: 450px;
    height: 250px;
    margin-top: 50px;
    display: flex;
    flex-direction: column;
    justify-content: space-evenly;
}
.reg form div {
    position: relative;
    color: black;
    display: flex;
    align-items: center;
    justify-content: center;
}
.reg form input {
    width: 200px;
    height: 25px;
    outline: none;
    border: 1px solid black;
    border-radius: 10px;
    margin-left: 20px;
    padding-left: 15px;
    box-sizing: border-box;
}
.reg form div:nth-child(3) input,button {
    width: 80px;
    height: 40px;
    border: none;
    background-color:skyblue;
    border: 1px solid black;
    border-radius: 5px;
    color: black;
    padding: 0;
}
.reg form div:nth-child(3) input {
    margin-right: 60px;
    background-color: skyblue;
}